LOS ANGELES -- Chris Brown was ordered to remain in a Los Angeles jail Friday after the R&B singer admitted he violated his probation by getting into an altercation outside a hotel in Washington, D.C., last year.

Superior Court Judge James R. Brandlin sentenced the singer to serve an additional 131 days in jail, although the term will likely be shortened by credits for good behaviour.

His mother and other supporters watched Friday's court proceedings, with some in the audience gasping when the singer was brought into court in handcuffs and jail attire.

Brandlin sentenced Brown to serve a year in county jail but gave him credit for nearly eight months. The credits include time that the singer has spent in rehab and jail, as well as credits for good behaviour while behind bars.

The Grammy-winning singer was on probation in a felony assault case after he attacked pop singer Rihanna, his then-girlfriend, hours before the 2009 Grammy Awards. In October, while on probation, Brown was accused of attacking a man outside a hotel in the nation's capital in October. He was charged with misdemeanour assault.

On Friday, Brown admitted he committed a crime in that case and waived his rights to an evidentiary hearing in which prosecutors would have to prove that Brown violated his probation.

Brown has been in custody since mid-March, when he was arrested after being expelled from a court-ordered rehab sentence for violating its rules.

Brown responded "Yes sir," repeatedly to questions posed by Brandlin during Friday's hearing, including a question about whether he was acknowledging he committed a crime in Washington, D.C. It is unclear whether that will have any impact on Brown's pending case.

Brandlin said Brown will have to complete the remainder of his 1,000 hours of community labour once he is released from jail. As of early February, Brown had 800 hours of community labour remaining.

The judge said he took into account that Brown was relatively young when he attacked Rihanna, and that he had a previously undiagnosed mental illness before the case began.

Brandlin ordered Brown into rehab in November and the singer was receiving treatment for anger management, substance abuse and issues related to bipolar disorder before he was dismissed in March.